1. Technical Field
The present invention relates to a floating-type sandy beach growing device, and more particularly, to a floating-type sandy beach growing device installed in water in sea or river to exert the wave absorbing capability, thereby preventing possible damages due to tsunami, high waves, and the like, and being contributable to growing of a sandy beach.
2. Description of the Related Art
In order to prevent possible damages resulting from tsunami, high waves, and the like, a variety of wave absorbing devices to be installed in a relatively shallow shore have been disclosed. Examples include a breakwater wherein a plurality of V-shaped bent bank bodies are provided in parallel with one another, being exposed from the water surface, and between adjacent bank bodies, a V-shaped bent water channel is provided (Japanese Unexamined Patent Application Publication No. Hei 6-212611), and a wave absorbing structure comprising one or more wave absorbing units which are each formed in the shape of an arc (substantially in the shape of a hemisphere) against a wave in any coming direction, and provided with a hollow chamber in the inside thereof, the hollow chamber being communicated with the seawater through an opening provided in the portion to be opposed to a wave in a typical coming direction (Japanese Unexamined Patent Application Publication No. Hei 10-237842).
These conventional wave absorbing devices are expensive in and of themselves due to their structures; are time-consuming for installation; and involve an increased total cost. To eliminate such drawbacks, the present inventor has already disclosed a wave absorbing method and a wave absorbing device, having a simple structure, being relatively low in cost of the device itself and installation cost, and yet providing an effective wave absorbing effect (Japanese Patent Publication No. 3609052).
The wave absorbing device in accordance with the invention as disclosed in Japanese Patent Publication No. 3609052 is a wave absorbing device comprising one or more wave absorbing bodies having an open side extending in the longitudinal direction and a C-shaped cross section, to be installed in water in a relatively shallow shore with the open side being oriented against the wave progress direction and angled with respect to the wave progress direction, and thereby, upon the wave hitting the offing side end of the wave absorbing body, allowing a flow to be created in the wave absorbing body by a water flow pressure difference caused between the inside of the offing side end of the wave absorbing body and the inside of the land side end thereof.
However, even in the case of this wave absorbing device, the cost of the wave absorbing body itself including the fixing piles and the cost of installation working therefor are high, and thus, the advent of a wave absorbing device the cost of which is suppressed to a less one has been earnestly demanded. In addition, with the aforementioned wave absorbing device, at the time of installation thereof, a great gap is produced between wave absorbing bodies, and there is the possibility that a wave may pass through the gap to make the wave absorption action of the device insufficient.
Patent document 1: Japanese Unexamined Patent Application Publication No. Hei 6-212611
Patent document 2: Japanese Unexamined Patent Application Publication No. Hei 10-237842
Patent document 3: Japanese Patent Publication No. 3609052
The present invention has been made in view of the problems with the aforementioned conventional wave absorbing device, and it is an object of the present invention to provide a floating-type sandy beach growing device which is free from the problem that a part of a wave may pass through the gap between wave absorbing bodies to impede the wave absorption action of the device; which can be constructed relatively easily and at a low cost; and which exerts a wave-absorbing action positively and effectively, resulting in a sandy beach being grown.